Flourimetry

What ??

Is flourimetry??

IT IS :

-It's a type of electromagnetic spectroscopy which analyze fluorescence from a sample.

- it involves using abeam of light , usually ultraviolet light

that excites the electron in molecule of certain compound and causes them to emit light

of a lower energy

THEORY

-Molecules have various

states of energy with

electronic and vibrational

states .

-Generally the species

being examined has:

1-aground electronic state

(a low energy state)

2-and an excited

(electronic state of higher

energy ) ,

* within each of these

electronic states are

various vibrational states .

Energy

e-Low energy level

excitation

High energy level Dropping

Emission of photon

of lower E

e-

How

THE EMITTED RADIATION IS MEASURED ???

By

Flourimeter

Components of Flourometer:

1- Source of energy2- Wavelength selector ( monochromator) 3- The cell 4- Detector 5- reader

CALCULATIONS

CONCENTRATION AND FLUORESCENCE INTENSITY : The power of fluorescent radiation, F, is proportional to the radiant power of the excitation beam absorbed by

the species able to undergo fluorescence: F = K'(P0 - P)

where P0 is the power incident on the sample, P is the power after it traverses a length b of the solution and K' is a constant which depends upon experimental

factors and the quantum efficiency of fluorescence.  

Beer's law can be rearranged to give:P/P0 = 10-bc

where A = bc is the absorbance. Substitution gives:

F = K'P0(1 - 10- bc)This is the fluorescence law

Unlike Beer’s Law fluorescence isn’t in general linear with concentration

 This expression can be expanded (Taylor series):

To a good approximation if bc is small (< 0.05) the higher-order terms are nearly zero, we have:

F = 2.3K'bcP0

Equation

-which demonstrates two important points:

1-that at low concentrations fluorescence intensity is proportional to concentration;

-at the absorption frequency   For a concentration above c1 the calibration curve is no longer linear

2-that fluorescence is proportional to the incident power in the incident radiation

Applications

1-Compounds which are fluorescent are determined easily

Ex : phenobarbitone , quinine , emetine ,adrenaline, cinchonine , vitamin a , riboflavine

2- nonfluoresent subsrances , can be determined after chemical reaction .

3- Inorganic ions can be determined by :-formation of flourescent chelatesEx : hydroxyquinoline >>> for Al Benzoin >>> for Zn flavanol >>> for Zr

References

http://en.wikipedia.org/wiki/Fluorescence_spectroscopy

http://medical-dictionary.thefreedictionary.com/fluorometry

http://www.answers.com/topic/fluorometry

http://www.google.com.eg/search?q=Fluorometry&hl=ar&gbv=2&prmd=imvnsb&tbm=isch&tbo=u&source=univ&sa=X&ei=iwbXTsiBCcmv8gOtoOjMDQ&ved=0CJMBELAE&biw=1280&bih=656

MADE BY : 1 -Aya Ahmed Saber Yosif 86

2 -Jehan Essam Mahmoud 1123 -Eman Mohammed Mostafa 83

4 -Basma Sayed Saeed Ahmed 5 -Bosy Nabil6 -Ayat Fwzy

7 -Eman Gamal8 -Gourge Reda 9 -Andro Esmat

10 -Jhon Esmat

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